Gun is focus of Melbourne shooting inquiry

A distinctive shotgun may have been used to shoot and wound a Melbourne policeman, detectives believe.

The short-barrelled firearm, with a long timber stock and ornate metal detailing, was found streets from where a Ford Escape SUV used in the shooting in Essendon eight days ago was dumped and torched.

Detectives say someone can probably recognise the unusual firearm and have urged anyone with information to come forward.

They have been investigating a possible link between the shooting, shots fired at gangland patriarch George Williams' Broadmeadows home shortly before the shooting, a fire bomb attack on a house in his street and another in the neighbourhood where Roberta Williams, former wife of gangland killer Carl, lives in Essendon.

But so far they say there is no evidence connecting the shooting with the latest attack on another house near Ms Williams' home early on Tuesday.